Research Area: Metabolic Disease Biological Activity: Ursodiol reduces cholesterol absorption and is used to dissolve (cholesterol) gallstones. (IC50=0.22 µM) It is one of the secondary bile acids, which are metabolic byproducts of intestinal bacteria. [1] A hit rate of around 0.4% was observed with a Z’ factor of 0.6 ± 0.2. Two confirmed hits are bile acids, chenodiol and ursodiol with an IC50 of 2.4 and 0.22 µM, respectively. [2]